Obesity May Impairs Mice Testicular Structure by STAT3/CYP19A1/Testosterone

Abstract

Obesity is an increasing serious global public health issue and a risk factor for male infertility. Aromatase expression level is elevated in obese men, and this high level is as-sociated with diminished serum testosterone levels. We explored the underlying mechanism of infertility in obese men. Genome-wide association study datasets were used to predict the causal relationship between obesity and male infertility. An obese male mouse model was generated by feeding mice a high-fat diet while control model was generated by feeding mice a normal chow diet. Serum indicators including free fatty acids, insulin, Follicle-stimulating hormone, and testosterone were measured using ELISA, and impaired fertility in mice was demonstrated using immunohistochemistry. The expression levels of STAT3 and CYP19A1 were measured by RT-qPCR and western blotting, respectively. Simultaneous bioinformatics analysis of publicly available data was performed using the R programming language and JASPAR database. Obesity might lead to male infertility from a genomic perspective. Obese mice displayed reduced serum testosterone and follicle stimulating hormone levels along with structural abnormalities, ectopic lipid deposition, and chronic inflammation in the testes. Upregulation of STAT3/CYP19A1 expression in obese mice was linked to reduced serum testosterone levels and impaired fertility. Our observation may support the hypothesis that since the elevation of STAT3 expression in obesity, the promoted expressed CYP19A1 could increase a shift from testosterone to estrogens. The persistently elevated level of estrogen will further stimulate STAT3, which may constitute a positive feedback loop. These findings provide new insights into the mechanisms of obesity-mediated male fertility impairment.